using System;
using System.IO;

using iTextSharp.text;

#region Mozilla Public License 1.1
/*
 * $Id: PdfIndirectObject.cs,v 1.3 2008/05/13 11:25:21 psoares33 Exp $
 * 
 *
 * Copyright 1999, 2000, 2001, 2002 Bruno Lowagie
 *
 * The contents of this file are subject to the Mozilla Public License Version 1.1
 * (the "License"); you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the License.
 *
 * The Original Code is 'iText, a free JAVA-PDF library'.
 *
 * The Initial Developer of the Original Code is Bruno Lowagie. Portions created by
 * the Initial Developer are Copyright (C) 1999, 2000, 2001, 2002 by Bruno Lowagie.
 * All Rights Reserved.
 * Co-Developer of the code is Paulo Soares. Portions created by the Co-Developer
 * are Copyright (C) 2000, 2001, 2002 by Paulo Soares. All Rights Reserved.
 *
 * Contributor(s): all the names of the contributors are added in the source code
 * where applicable.
 */
#endregion LICENSE

namespace iTextSharp.text.pdf
{
    /**
     * <CODE>PdfIndirectObject</CODE> is the Pdf indirect object.
     * <P/>
     * An <I>indirect object</I> is an object that has been labeled so that it can be referenced by
     * other objects. Any type of <CODE>PdfObject</CODE> may be labeled as an indirect object.<BR/>
     * An indirect object consists of an object identifier, a direct object, and the <B>endobj</B>
     * keyword. The <I>object identifier</I> consists of an integer <I>object number</I>, an integer
     * <I>generation number</I>, and the <B>obj</B> keyword.<BR/>
     * This object is described in the 'Portable Document Format Reference Manual version 1.3'
     * section 4.10 (page 53).
     *
     * @see        PdfObject
     * @see        PdfIndirectReference
     */

    public class PdfIndirectObject
    {

        // membervariables

        /** The object number */
        protected int number;

        /** the generation number */
        protected int generation = 0;

        internal static byte[] STARTOBJ = DocWriter.GetISOBytes(" obj\n");
        internal static byte[] ENDOBJ = DocWriter.GetISOBytes("\nendobj\n");
        internal static int SIZEOBJ = STARTOBJ.Length + ENDOBJ.Length;
        internal PdfObject objecti;
        internal PdfWriter writer;

        // constructors

        /**
        * Constructs a <CODE>PdfIndirectObject</CODE>.
        *
        * @param        number            the objecti number
        * @param        objecti            the direct objecti
        */

        internal PdfIndirectObject(int number, PdfObject objecti, PdfWriter writer)
            : this(number, 0, objecti, writer)
        {
        }

        internal PdfIndirectObject(PdfIndirectReference refi, PdfObject objecti, PdfWriter writer)
            : this(refi.Number, refi.Generation, objecti, writer)
        {
        }
        /**
        * Constructs a <CODE>PdfIndirectObject</CODE>.
        *
        * @param        number            the objecti number
        * @param        generation        the generation number
        * @param        objecti            the direct objecti
        */

        internal PdfIndirectObject(int number, int generation, PdfObject objecti, PdfWriter writer)
        {
            this.writer = writer;
            this.number = number;
            this.generation = generation;
            this.objecti = objecti;
            PdfEncryption crypto = null;
            if (writer != null)
                crypto = writer.Encryption;
            if (crypto != null)
            {
                crypto.SetHashKey(number, generation);
            }
        }

        // methods

        /**
        * Returns a <CODE>PdfIndirectReference</CODE> to this <CODE>PdfIndirectObject</CODE>.
        *
        * @return        a <CODE>PdfIndirectReference</CODE>
        */

        public PdfIndirectReference IndirectReference
        {
            get
            {
                return new PdfIndirectReference(objecti.Type, number, generation);
            }
        }

        /**
        * Writes eficiently to a stream
        *
        * @param os the stream to write to
        * @throws IOException on write error
        */
        internal void WriteTo(Stream os)
        {
            byte[] tmp = DocWriter.GetISOBytes(number.ToString());
            os.Write(tmp, 0, tmp.Length);
            os.WriteByte((byte)' ');
            tmp = DocWriter.GetISOBytes(generation.ToString());
            os.Write(tmp, 0, tmp.Length);
            os.Write(STARTOBJ, 0, STARTOBJ.Length);
            objecti.ToPdf(writer, os);
            os.Write(ENDOBJ, 0, ENDOBJ.Length);
        }
    }
}